Calibrating friction coefficients in discrete element method simulations with shear-cell experiments
Calibrating friction coefficients in discrete element method simulations with shear-cell experiments
复制标题
DOI：
10.1016/j.powtec.2020.05.079
复制
发表时间：
2020-07
影响因子：
5.2
通讯作者：
Andrew C. R. Angus;L. A. A. Yahia-L.-A.-A.-Yahia-94396078;Riccardo Maione;Marv J. Khala;C. Hare;A. Ozel;R. Ocone
中科院分区：
文献类型：
--
作者：
Andrew C. R. Angus;L. A. A. Yahia-L.-A.-A.-Yahia-94396078;Riccardo Maione;Marv J. Khala;C. Hare;A. Ozel;R. Ocone
离散元法（DEM）模拟与剪切单元的实验结果已被用来研究在准静态制度的玻璃珠的干颗粒组件的流动行为。使用FT 4粉末剪切单元装置进行了实验研究，同时对均匀简单剪切和FT 4剪切单元本身进行了广泛的DEM模拟。研究结果表明，它是不可能准确地预测体摩擦系数与均匀简单剪切模拟，除非滚动和滑动摩擦被认为是。然而，有多对滑动和滚动摩擦系数，可以重现实验体摩擦系数。进行滑动测试实验以产生滑动摩擦系数，从而最小化潜在正确对的集合。然后，对具有两个不同校准对的完整FT 4剪切单元进行模拟，沿着具有没有滚动摩擦的校准对，以了解它们的选择对现实壁边界剪切条件的影响。离散主要发现在所获得的径向接触数和速度分布，增加摩擦系数-特别是滑动摩擦-发现抑制剪切变形区中的填料和颗粒速度。均匀简单剪切和剪切单元模拟结果之间的比较表明，获得的力网络上的墙壁的显着影响，几乎完全没有最弱的结构，被视为支持强结构在简单剪切的情况下。
Discrete Element Method (DEM) simulations coupled with shear cell experimental results have been used to investigate the flow behaviour of a dry particle assembly of glass beads in the quasi-static regime. Experimental studies have been undertaken using an FT4 powder shear cell apparatus, in parallel with extensive DEM simulations of both homogeneous simple shear and the FT4 shear cell itself. The findings show that it is not possible to accurately predict the bulk friction coefficient with homogeneous simple shear simulations unless both rolling and sliding friction are considered. There are, however, multiple pairs of sliding and rolling friction coefficients which can reproduce the experimental bulk friction coefficient. Sliding test experiments were conducted to yield the coefficient of sliding friction, and hence minimise the set of potentially correct pairs. Simulations of the full FT4 shear cell with two different calibration pairs, along with a pair without rolling friction, were then undertaken to understand the effect of their selection on realistic wall-bounded shearing conditions. Discrepancies were mainly found in the obtained radial contact number and velocity profiles, with increasing friction coefficients - particularly sliding friction - found to inhibit packing and particle velocity in the shear deformation zone. Comparison between homogeneous simple shear and shear cell simulation results showed a significant effect of the wall on the obtained force network, with almost a complete absence of the weakest structures which were seen supporting the strong structures in the simple shear scenario.